I think this card will work for pretty much any female - stitchers, knitters, crafters, WI members, #thisgirlcan, christmas funnies, you name an occasion I'm pretty sure it will work.
 
These are a5 in size (that's half the size of a piece of standard a4 paper) 14.8 x 21cm - and fits the criteria for a small letter when sending via royal mail.
 
Blank inside for your own special message